In the Garden | Vegetable-garden harvesting do's and don'ts

During the hottest part of the summer, tomatoes need to be harvested sooner and more frequently to ensure the highest quality.

Harvesting vegetables from your garden can sometimes be tricky. Each individual crop has specific considerations for harvesting the best-tasting and most long-lasting produce.

In general, the quality of your vegetable crop will not improve after harvest, so timing can be critical. It is important to understand how vegetable crops mature and should be harvested. In addition, many crops have guidelines for storage post-harvest that are often misunderstood or unknown by many.

Below is information about a few common vegetable crops in central Illinois gardens.

TOMATOES

Proper harvesting and short-term storage of tomatoes are common questions among gardeners. For the best taste, tomatoes should be harvested when firm and fully colored.

The best quality tomatoes occur when temperatures are around 75 degrees, which does not span much of our growing season. When temperatures approach 90, the softening process is greatly accelerated, color development is slowed and quality is reduced, especially if left on the vine too long.

During hotter weather, it is best to harvest tomatoes when color has started to develop (so they aren't green any longer, often having a pink color, but certainly not red yet). Store these early harvested fruits indoors, a sunny spot near a window is best, to allow further ripening. Refrigeration inhibits further ripening, alters the fruit and reduces shelf life. So, do not refrigerate whole, uncut tomatoes.

BELL PEPPERS

Peppers are harvested in a variety of sizes and stages of maturity. This timing will largely depend on the variety planted, so pay attention when you are buying seed or seedlings.

Most green pepper varieties are harvested when fully grown and mature. At maturity, they will be 3 to 4 inches long and a full green color. Mature peppers break easily from the stem (which is a good field test), although some damage to plant may be saved by actually cutting them off.

Colored bell peppers are a different story. For most varieties of colored peppers (red, yellow, orange), the fruit should be allowed to fully ripen to their specific color in order to achieve full flavor.

The fruits will begin green colored and develop their individual color at maturity. They may be harvested at an immature, green stage if desired, but flavor is sacrificed.

Other varieties of colored peppers achieve their greatest color in immature stages (white, light yellow, purple) and should be harvested before actually ripening to a red color if maximum color is desired.

Ideal post-harvest storage of peppers (50 to 55 F, 60 percent relative humidity) are conditions typically not met in the average kitchen or refrigerator. Under ideal conditions, shelf life is about two weeks. Refrigerators are typically a little cooler (around 40 F) but can be sufficient, although shelf life may suffer.

Store unwashed peppers in a perforated plastic bag in your refrigerator; solid plastic bags cause excess moisture and reduce shelf life. Under typical conditions in a refrigerator, expect an average shelf life of about one week.

SUMMER SQUASH

Summer squash, like zucchini and yellow squash, can quickly become overripe and harvesting at the correct time may take diligence as squash ripen about four to eight days after flowering.

On the positive side, a healthy squash vine produces an enormous amount of fruit. Ideal harvesting size is about 6 to 8 inches in length and 1 to 2 inches in diameter, when squash are small and tender. A glossy outer color may indicate tenderness.

After harvesting, store in a cool spot (55 F is ideal) or in a refrigerator within a perforated plastic bag to allow sufficient airflow to the fruit surface. Do not store in the refrigerator more than about four days. Under ideal conditions, expect a shelf life of one week.

Many of us let squash get too large before harvesting, but don't lose hope. An overripened squash that is slightly larger than ideal, not the size of a baseball bat, can still be used for some things. It can easily be used for stuffing by hollowing out the inner seedy area, filling it with delicious fixings and baking. Similarly, overripe squash can be grated for baking and added to other recipes, after removing the inner seeds.

Do not let squash become large as it will be seedy and tough. It is imperative to harvest fruits before they become overly large because your squash plant may waste excessive energy on growth that could be otherwise focused on smaller, more ideal-sized fruits.

Ryan Pankau is a horticulture educator with the University of Illinois Extension, serving Champaign, Ford, Iroquois and Vermilion counties.